<title>Models for calculation of dielectric permittivity of moist sandy-clayey soils in wide range of frequencies</title>

Abstract

Detailed physical model of dielectric permittivity of sandy- clayey soils is proposed. The model is based on mixture formulas, which are applied in several steps, by which different components of the soil are successively combined. Several mixture formulas have been tested when applied to mixtures with flattened and spherical inclusions. For a mixture with very flattened inclusions Maxwell Garnett's mixture formula gives most accurate results. It is shown, that Maxwell-Wagner effect in clay in frequency range from approximately 1 - 5 to several hundreds MHz may be described by Maxwell Garnett's and Bruggeman's formulas. Five models are proposed to describe the Maxwell-Wagner effect in clay. Results of modeling are compared with results of measurements. The models with few parameters, adjusted for a given clayey soil, describe this soil depending on moisture and temperature, including a range below 0 degree(s)C. These parameters depend only on soil and do not depend on moisture and temperature. The model of soil takes into account distribution of water between clay and soil solution, change of thickness of bound water layers depending on moisture and when freeze. Conductivity of bound water, it's temperature dependence have been found for some soils. Debye relaxation spectrum of bound water was studied.